Cooling rolling mill



March '14, 1939. 9 OHN 2,150,340

COOLING ROLLING MILL Filed Sept. 27, 1937 {@UUUEM ig-[35mm I WILJ! lL IFig.4

Adarnqy Patented Mar. 14, 1939 UNITE STATES PATENT OFFiQE ApplicationSeptember 27, 1937, Serial No. 165,909 In Germany October 5, 1936 11Claims.

The present invention relates to means for cooling so-called multi-highrolling mills, for example 12 high and 20 high rolling mills.

Fig. l is a front view, partly in cross-section,

of the rolls of a twenty-high rolling mill;

Fig. 2 is a fractional view, partly in cross-section, of an intermediatespace of a twenty-high rolling mill; f

Pig. 3 is a diagrammatic view showing the arrangement of twocooling-pipes;

Fig. 4 is a diagrammatic view showing another rangement of twocooling-pipes;

The arrangement of the rolls in a high rolling mill is illustrated inFigure l, in which A are 16' the working rolls, B the rolls whichsupport the working rolls, C further supporting rolls for theintermediate rolls B and D are the outer supporting rolls. The referenceletters L represent strips of packing material, for example of felt orleather.

20 These multi-high rolling mills enable working rolls of very smalldiameter to be employed and consequently a very great reduction can beeffected at each pass, Owing to this, however, excessive heating of therolls, and in particular of the working rolls, occurs and it isimportant to conduct this heat sufiiciently rapidly away from the rolls,the more so because their capacity for taking up heat is onlysmall. Theknown cooling devices by which the cooling liquid'simply trickles .30from the outside over the surface of the rolls or is sprayed on to themare not suiilcient because. if the rolls are merely sprinkled withliquid, the

heatis not conducted away suillciently quickly from the very smallaccessible surface of the working rolls and is not conducted away at allfrom the places indicated by the letters a and b in Figure 1. This isonly possible if provision. be made for a cooling medium, for examplecooling oil or an emulsion of oil and water, to flow with 40 suflicientspeedthrough the intervening spaces 0, d and e, I located between theplaces a and b, and the velocity of flow has a component of considerablemagnitude parallel to the axis of the rolls. If for this purpose thecooling medium is 5 allowed to flow from one end face of the rolls inthe longitudinal direction of the rolls through the intermediate spaces0, d and e, I and a device for carrying away the oil is provided at theother end face of the rolls, the desired result may indeed be obtained,provided the rolls are not 7 on too heavy duty and, more particularly,if the length of the rolls is not excessively great. Inv

the case of rolls which are on particularly heavy rolling and of rollsof very great length it has been found that thecooling medium is heatedup considerably while it flows along the surface of the rolls throughthe intermediate spaces 0, d and e, f, the consequence of which is thatthe rolls become heated up at one end and increase slight-- ly indiameter at this end, that is to say the pass between the rolls does notremain uniform along the entire length of the working rolls. This couldbe partially compensated. by allowing the cooling medium to flow fromright to le'ft,along the upper rolls and from left to right along thelower rolls. If this were done, however, both sets of rolls become veryslightly conical which would iii lead to forced slipping-and torsionaloscillations and thereby to disturb the rolling operation. In order toavoid these disadvantages, according to the present invention thecooling medium is'not introduced only at one end face of the rolls intothe intermediatespaces c, d and e, 1 but is introduced from both enolfaces of the rolls, for example it enters through c and e and escapesfrom d and f. This cari be done, for example, by. providing a supply ofcooling medium of the ,kind shown in Figure 2. I

Figure 2 is a side view of the upper working roll A and the uppermostsupporting roll 0, the

intermediate block K and the pipes E, E, F, F being shown in verticalcross-section. In this figure A indicates the surface of the roll Awhich faces the space 0, and C represents the surface of the roll Cwhich faces the spaces 6. The narrowest part of the hollow space between0 and d is indicated by the dotted line BIL-M. The cooling medium is nowpumped in, for example through pipes E and E at both ends of the roll Ainto the hollow space 0 and is conducted 0 away through the pipes F andF in the hollow space d towards both end faces of the rolls. Thedirection of flow of the cooling medium is indicated by arrows. Thecooling medium can, however, also be allowed to flow in the reversedirection through the pipe system. Which of the pipes F and E must bemade shorter and which must be led to the centre of the hollow spacewill depend on the work which is being performed by the rolls at thetime. In the arrangement illustrated, the ends of the working rolls arecooled most strongly and the middle is cooled least because the coolingmedium has already become slightly warmer there. The result of this isthat the working rolls become slightly'thicker in the middle, that is tosay they become slightly convex and therefore the crown is. increased.

By a suitable choice ofthe direction of. flow and of the lengths of thepipes the middle of the rolls can be kept cooler than the ends of therolls lit ' and the convexity or the crown is reduced so that the rollscan, to a large extent, be adapted to suit the kind of work which isbeing done at any time, i. e., they can be adapted to suit materials ofgreater or less hardness, or of diflerent widths, as well as to thereduction desired to be efiected per each pass or to meet differences inthe thickness of the original strips between its edges and its center.The cooling medium can be introduced into the spaces e, f in a similarmanner to that indicated in Figure 2 for the spaces 0, d and theconvexity, i. e., the crown of the intermediate and outer supportingrolls can thereby be influenced in a corresponding manner. For example,when the working rolls have a diameter of 50 mm. and a length of 850 mm.and a power of 1000 kilowatts is employed, the supply of cooling mediumcan be regulated in such a waythat the difierence of temperature at themiddle and ends of the working rolls amounts to 50 C. In this case theincrease in the diameter of the rolls at the hottest places as comparedwith its diameter at the coolest place is 0.03 mm., which gives therolls a crown which is desirable for rolling dead soft annealed mildsteel strip of 600 mm. width. In the case of the supporting rolls of 500mm. diameter. a temperature difference of 10 C. between the middle andends of these rolls produces an increase in diameter of 0.06 mm. r

In order now to be able to eilfect a particularly fine regulation of thediflerence in temperature between the middle and the ends of the rollsthe device which is hereinafter described may be employed. For thispurpose, for example, the pipe F' which extends up to the central planeof the rolling mill is provided in the manner indicated in Figure 3 withopenings which are uniformly distributed over its length in such amanner that the cooling medium flowing through the 'pipe F can escapethrough these openings. By means of a second pipe which is disposedinside or outside the pipe F and is longitudinally displaceable orrotatable relatively to the pipe F, some of the openings can be closedand the flow of cooling medium can thereby be controlled to flow mostlyat the end or mostly at the middle. This arrangement is illustrated indetail in Figures 3 and 4. In Figure 3 the pipes F and G which areactually arranged concentrically to one another are shown one above theother. The pipe F has openings H, the distance between each one of thembeing equal to the diameter or width of the openings. concentrically tothe pipe F has openings J which are of the same size as the openings Hin the pipe F. In the example illustrated in Figure 3 the openings H andJ coincide exactly at one end of the pipes F and G, while at the otherend they are relatively displaced by a distance equal to the width ofone of the openings. When the pipes are in the position illustrated inFigure 3, the opening at the extreme right of the pipe F is opened andthe opening at the extreme left of the pipe is closed so that the oilescapes for the most part at the right-hand end of the pipe F. If nowthe pipe G is axially displaced so that its extreme left-hand openingcoincides with the extreme left hand opening of the pipe F, then theextreme right-hand opening of the pipe F is closed completely and thecooling medium flows away at the side of the rolls to a considerablygreater extent than previously. The pipes can also be adjusted to anyintermediate position between these extreme positions. By this means anyirregulariother.

provided at the center of the spaces.

The pipe G which is arranged ties in the thickness of the hot-rolledstarting material can be partly or fully compensated.

Another form of construction is illustrated in Figure 4. In this thepipe G is not displaceableaxially along the pipe F but is rotatable.Both pipes are again arranged concentrically one to the In this case,however, the openings in the pipeG do not lie in a horizontal plane butare disposed in such a manner that when the openings Hand J on theextreme right hand end 01' the, pipes coincide, that is to say theextreme right-hand opening is free for the oil to flow out, the openingsat the other end donot coincide and no oil can escape from the pipe F atthis end.

It may be advisable in some cases to provide separate cooling systemsfor the individual intermediate spaces c, d and e, f. The conduct ofheat away from intermediate spaces 0, d is particularly vided for itsoutflow, for example for preventing the cooling medium from the pipe Efrom escaping through the pipe F, a fitting piece K can be The fittpieces may be for example of artificial resin, and can be flxed on theends of pipes F and F.

The pipes by which the cooling medium enters and leaves. may also bearranged in such a way that they are axially displaceable, i. e., in thelongitudinal direction of therolls. By this means the outlet or outletsfor the cooling medium can be displaced at will in the longitudinaldirection of the rolls whereby the removal of the heat from the rollscan be regulated.

Iclaim: v 1. The method of cooling multi-high rolling mills whichconsists in pumping a cooling medium through the intervening spacesbetween the rolls, the pressure of the cooling medium pumped through theintervening spaces adjacent the working rolls being higher than thepressure of the cooling medium pumped through the remaininginterveningspaces between the supporting rolls.

2. The method of cooling multi-high rolling mills which consists inpumping a cooling medium through the intermediate spaces adjacent theworking rolls under high pressure, and then conducting the mediumescaping from the said spaces through the remaining intervening spacesbetween the supporting rolls.

3. In a multi-high rolling mill a system of pipes extending into theintervening spaces between the rolls nearly to the center of the rolls,another system of pipes extending from outside into the said interveningspaces, means for admitting a cooling medium to part of the pipes andwithdrawing it through the other, and means for axially displacing thepipes.

4. In a multi-high rolling mill a system of pipes extending into theintervening spaces between the rolls nearly to the center of the rolls,an other system of pipes extending from outside into the saidintervening spaces, means for admitting a cooling medium to part of thepipes and withdrawing it through the other, and means for rotating thepipes.

5. The method of cooling. muiti-high rolling mills which consists inconducting from both ends of the rolls a cooling medium'into theintervening spaces between the rolls, bounded at all sides by thecylindric roll surfaces, in a direction parallel to the axes of therolls, and leading off the cooling medium from the center of theintervening spaces.

6. The method of cooling multi-high rolling mills which consists inconducting from both ends of the rolls a cooling medium'into theintervening spaces between the rolls. bounded at all sides by thecylindric roll surfaces, in a direction parallel to the axes of therolls, leading 01! the cooling medium from the center of the interveningspaces, and regulating the quantity and the rate of flow of the coolingmedium insuch a manner that a desired degree of convexity or crown isimparted to the rolls.

' '7. In a multi-high ro1l1n8 mill. 8. number of pipes considerablyshorter than one half the length of the rolls, a number of pipes havingabout half the length of the rolls, both kinds of pipes extending fromboth ends of the rolls into the intervening spaces bounded by thesurfaces of the rolls, and means for introducing a cooling medium fromoutside into one kind of the s. 8. In a multi-high rolling mill, pipesextending from both ends of the rolls into the intervening spacesbounded by the surfaces of the rolls, part of the pipes reaching nearlyto the center of the said spaces and part of them being provided withperforations distributed over their length, means for introducing acooling medium from, outside into a number of the pipeaand means forclosing and opening the said perforations in a predetermined manner.

9. In a multi-high rolling mill, pipes, extend,-

ing from both ends of the rolls into the intervening spaces bounded bythe surfaces of the .rolls, part of the pipes reaching nearly to thecenter of the said spaces and part of them being provided withperforations distributed over their length,'other perforated pipesarranged coaxially with the said perforated pipes, means for introducinga cooling medium from outside into a number of the pipes, and means formaking coincide a desired part'of the perforations in the coaxial pipes.

10. Ina multi-high rolling mill, pipes extending from both ends of therolls into the intervening spaces bounded by the surfaces of the rolls,part of the pipes reaching nearlyto the center of the said spaces andpart of them being provided with perforations distributed over theirlength, other perforated pipes arranged coaxially with the saidperforated pipes, means for introducing a cooling medium from outsideinto a number of the pipes, and means for moving the pipes parallel tothe axes of the rolls aridv thereby making coincide a desired part ofthe perforations in the coaxial pipes,

11. In a multi-high rolling mill, pipes extending from both ends of therolls into the intervening spaces bounded by the surfaces of the rolls,part of the pipes reaching nearly to the center of the said spaces andpart of them being provided with perforations distributed over theirlength, other perforated pipes arranged coaxially with the saidperforated pipes, means for introducing a cooling medium from outsideinto a number of the pipes, and means for rotating the pipes aroundtheir axes and thereby making coincide a desired part of theperforations in the coaxial pipes.

WILHELM RDHN.

